Improvement in fire-plates for boiler-furnaces



N ETiENNE BOILEAU. Improvement in Fire Plates for Boiler Furnaces.

Patented Oct. 13,1871.

UNrrnn STATES PATENT QFFICE- ETIENNE BOILEAU, OF ST. LOUIS, MISSOURI.

Specification forming part of Letters Patent No. 119,562, dated October3, 1871.

To all whom it may concern:

Be it known that I, ETIENNE BOILEAU, of the city and county of St. Louisand State of Missouri, have invented certain new and useful Improvementsin Fire-Plates for Furnaces, Stoves, &c., of which the following is aspecification:

This invention relates to improvements on the fire-plates patented to methe 6th day of July, 1869, No. 92,253. My present improvement consistsprincipally in carrying the narrow slots in the plate almost to itsupper edge, so as to preserve the upper edge from fusion, as it wasfound liable to be destroyed by heat in the hotter class of furnaces.

The drawing represents my fire-plates as applied to a boiler-furnace.

Figure 1 is longitudinal section at the line Y Y, Fig. 2, of aboiler-furnace to which my fire-plates are applied. Fig. 2 is atransverse section of the same at line X X, Fig. 1. Fig. 3 is anenlarged perspective View of the rear and side fire-plates. Fig. 4 is ahorizontal section of a portion of one of the fire-plates. J

A is the steam-boiler, supported in the usual manner. B are the sidewalls of the furnace. O are the grate-bars, that may be of any form. Dis the bearing-bar supporting the rear end of the grate-bars. E is thebridge-wall. F F are, respectively, the rear and sidefire-p1ates,theybeing similar in the main points of construction, buthaving some minor difl'erences to fit them for their particularsituations. These fire-plates have slits or slots 9, very narrow at thefire-face, but widening toward the back of the plate, and extendingalmost the whole distance from the bottom H to the top I. These slotsmay be made one-fourth of an inch wide at the fire-face andthree-fourths of an inch, more or less, at the back of the plate. Theplates may be made three inches in thickness. The bars G of the platemay be made three-fourths of an inch thick at the fireface, and may be asixteenth of an inch thick at the rear part. At the upper end of theslots 9 are enlargements 9 forming passages for the heated air, and bytheir direction acting to project the air into the firespace above thefuel. The plates F have rabbets K to receive the corner of the grate-barupon which the plate is supported. L is a lug that rests against theside of the wall B to hold the lower end of the plate at the properdistance therefrom. At the upper edge of this plate are holes f, toreceive bolts M passing through the walls B. The plates F when inposition, are slightly inclined backward, as shown in Fig. 2, so thatthe air-space between the plate and the wall is narrower at top thanbottom. f

are notches forming air-passages between the wall and the plate. Theplates F are made somewhat longer than those F so that when. they areinclined at an angle of about forty-five degrees, more or less, theirtop will be at the same level as that of the plates F as shown inFig. 1. The lower ends of the plates F rest on the bearingbar Dand'their upper ends againstthe bridgewall E, with whose top they shouldbe about flush. F is a triangular plate, made to fit the space betweenthe inner plate F and the plate F. It is similarly slotted to the platesF and F The slots G have four purposes, first, to allow the expansionand contraction of any portion of the plate without affecting theremainder; second, the circulation of cool air in proximity to thefireface to prevent the overheating of the metal; third, the heating ofthe air for the purpose of consuming the smoke; and fourth, allowing thepassage of a small quantity of air into the fire. The first threepurposes I conceive to be of much the greater consequence, and, in fact,to constitute the valuable elements of the plate.

In the use of my plate, as described in patent No. 92,253, in furnacesof steam-boilers, I found that the portion between the upper ends of theslots and the jet-holes became overheated and destroyed, and to obviatethis difficulty I extended the slot upward so as to communicate with thesaid jet-holes, and the circulation of air in the said upward extensionwas. found to fully answer the purpose intended, the upper edge of theplate becoming sufficiently refractory.

Where a solid tile is used at the bridge-wall the clinkers become cakedagainst the same, and where open grate-bars are used in that positionthe fire varies in temperature to such an extent as to disastrouslyaffect the boiler at that point;

and the bars also become quickly destroyed.

plates are varied according to circumstances. For instance, forapplication to a locomotive-furnace the plates F would be made shorterand inclined less from the vertical, and in any case the plate might bemodified in form' to meet the requirements and to render it applicableto all kinds of fire-places, stoves, and furnaces.

I claim as my invention- The fire-plates F F F, having narrow slits orslots g, terminating at the upper end in air-passages 9 substantially asset forth. 7

In testimony of which invention I hereunto set my hand.

ETIENNE BOILEAU.

Witnesses SAML. KNIGHT,

R. T. BRADLEY. (72)

